The first determination of Generalized Polarizabilities of the proton by a Virtual Compton Scattering experiment

TL;DR

This paper reports the first experimental determination of the generalized polarizabilities of the proton through a virtual Compton scattering experiment, providing new insights into proton structure at specific momentum transfer.

Contribution

It presents the first measurement of structure functions related to generalized polarizabilities of the proton using virtual Compton scattering at MAMI.

Findings

First determination of structure functions related to proton polarizabilities

Measured differential cross sections at specific Q^2 and photon momenta

Provided new data for proton internal structure analysis

Abstract

Absolute differential cross sections for the reaction (e+p -> e+p+gamma) have been measured at a four-momentum transfer with virtuality Q^2=0.33 GeV^2 and polarization \epsilon = 0.62 in the range 33.6 to 111.5 MeV/c for the momentum of the outgoing photon in the photon-proton center of mass frame. The experiment has been performed with the high resolution spectrometers at the Mainz Microtron MAMI. From the photon angular distributions, two structure functions which are a linear combination of the generalized polarizabilities have been determined for the first time.